Suggestions

The first book, this is what I'm doing

Also, head's up warnings before you read the book:
1. Mentions of IRL events like WW2 ( barely )
2. Countries you may not want to see ( Example: Soviet Union )
3. Words you may not like, for example, swearing words or just words you get triggered with
4. Ships ( they will be barely mentioned though, but there are ships you might disagree on or you entirely don't like ships, which I do respect your opinion on it )